Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of the common general knowledge in the field.
Electronic readers, also known as e-readers or e-books, are becoming an increasingly common alternative to traditional books and other publications. Electronic readers typically comprise a reflective display that presents to a viewer pages from a publication held in the memory of the electronic reader, but it will be appreciated that any type of transmissive or emissive display could be used. Known reflective displays include electrophoretic (or ‘electronic ink’), MEMS and electrowetting technologies. Some electronic readers currently available have a touch screen interface that enables a user to turn pages with a finger swipe instead of pressing a physical button. However on current touch-equipped devices the touch screen is of a resistive or capacitive type, meaning that there is at least one conductive layer interposed between the display and a viewer. These conductive layers are typically composed of indium tin oxide (ITO), which has a refractive index of approximately 2.0, substantially different from that of the glass or plastic e-reader display (approximately 1.4 to 1.6). This refractive index differential causes glare, and furthermore the ITO films are only partially transparent, typically absorbing 20 to 30% of visible light; both these factors degrade the viewability of the display, particularly since reflective displays are generally not backlit for reduced power consumption i.e. extended battery life. Some electronic readers use an inductive touch sensor (e.g. from Wacom Co, Ltd) located behind the display to avoid the use of overlays, however these sensors require the use of a special inductive pen and cannot readily detect finger touch.
Besides the page turn function, touch screen-equipped e-readers often provide a separate ‘annotation’ mode that the user can enter, for example to make notes on the e-book page. However the user then has to leave the annotation mode to return to the default page turn mode, so that a user may constantly have to switch between modes.